This grant is a competing renewal with the long-range goal of understanding how cytokines initiate and perpetuate PVR. This application is based on the hypothesis that HA is an important regulator of cytokine production by RPE, that the cytokines influence monocyte recruitment, which in turn perpetuates the wound healing response. To test the hypothesis, the following aims are proposed: (1) to determine the effect of HA on cytokine production, cell proliferation, and cell migration in cultured human RPE and to determine if the effects are mediated by HA receptors; (2) to determine if subretinal fluid (SRF) from patients with rhegmatogenous retinal detachment (RRD) influences cytokine production by human RPE cells and monocytes and what role HA may play in this; and (3) to determine which specific cytokines are in the SRF of eyes with rhegmatogenous retinal detachment that can influence the migration and survival of human monocytes.